It is estimated approximately 30% of cases of couple infertility are due to a male factor. Several conditions can interfere with spermatogenesis and reduce sperm quality and production. Oxidative stress is a leading cause of male infertility, as it leads to decreased sperm count and motility and causes damage to sperm DNA.
An estimated six percent of adult males are thought to be infertile. Infertility is defined generally as the inability to achieve a pregnancy after one year of unprotected intercourse. Conception is normally achieved within 12 months in 80-85 percent of couples using no contraceptive measures; thus, an estimated 15 percent of couples attempting their first pregnancy will have difficulty conceiving. While certain cases of male infertility are due to anatomical abnormalities such as varicoceles, ductal obstructions, or ejaculatory disorders, it has been shown that an estimated 40-90 percent of cases are due to deficient sperm production of unidentifiable origin.
A normal semen sample have a volume of 1.5-5.0 ml, with greater than 20 million sperm/mL. Without being bound by any theory, it is believed that to achieve conception the number of abnormally shaped sperm should be less than 40 percent, with 50 percent or more of the sperm sample demonstrating proper motility.
Unfortunately, there is a growing body of scientific evidence supporting the idea that sperm counts in male have declined considerably over the last 50 years. Three recent reports also found semen quality has declined among donors over the last 20 years. Because the decline in sperm production is relatively recent, it is believed that a combination of environmental, lifestyle, and dietary factors may be interfering with spermatogenesis.
Oxidative stress has been shown to be a major cause of male infertility. A large proportion of infertile men have elevated levels of seminal reactive oxygen species (ROS). High concentrations of ROS cause sperm pathology such as ATP depletion leading to insufficient axonemal phosphorylation, lipid peroxidation and loss of motility and viability.
A commonly assigned U.S. Pat. No. 8,974,838, issued Mar. 10, 2015, which is incorporated herein by reference in its entirety, provides a nutritional supplement comprising a sperm count enhancing dose of Lepidium meyenii to improve male infertility. However, there still is a need for other nutritional supplements for enhancing male fertility, especially in which the male infertility is believed to be due to oxidative stress and/or reduced sperm motility.